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US 4,539,019 AGranted
Control system for air fractionation by selective adsorption
AssigneeAir Products and Chemicals, Inc.
InventorWilliam R. Koch
Life of this patent
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AssigneeAir Products and Chemicals, Inc.
InventorWilliam R. Koch
Estimating the term…
In a cyclic VSA system for air fractionation by selective adsorption of nitrogen from the feed air during an on-stream adsorption period in said cycle in which period an oxygen-enriched primary effluent discharged from the adsorption column is collected in a surge vessel, the duration of the on stream adsorption step is automatically controlled by a sensing device monitoring inventory of gas collected in said surge vessel. In an alternative embodiment the adsorbed nitrogen is withdrawn by vacuum desorption of the column and collected in a second surge vessel, from which second vessel a portion of the nitrogen is subsequently withdrawn for use in rinsing the nitrogen laden column, said second surge vessel being likewise equipped with inventory monitoring means operative for automatically controlling the extent of the rinsing step. Alternately, when nitrogen is collected in a second surge vessel, the system may be operated by inventory monitoring of both surge vessels or only one surge vessel wherein another technique is used to control the other surge vessel.
In the operation of a cyclic system for recovery of an enriched-oxygen effluent product by selective adsorption of nitrogen from an ambient air feed stream, wherein said ambient air previously freed of contained water and CO.sub.2 is passed through a bed of solid adsorbent selective in retention of nitrogen as opposed to oxygen, with resulting production of an oxygen-enriched gaseous effluent which is withdrawn from said bed and collected in a receiver;
In the fractionation of air by a vacuum swing adsorption process comprising the sequential steps of (1) introducing the air, freed of water and CO.sub.2, into a bed of adsorbent selective in retention of nitrogen and collecting the unadsorbed oxygen-enriched effluent in a first receiver;
In a cyclic system for fractionation of air wherein during an on-stream period nitrogen is selectively adsorbed from the feed air in an adsorption column while collecting and storing in a surge vessel the oxygen-enriched primary gas effluent discharged from said adsorption column, and wherein the column laden with adsorbed nitrogen is subsequently desorbed under vacuum;
In a vacuum swing adsorption system for the fractionation of air wherein air free of water and carbon dioxide is introduced into a column of adsorbent selective in retention of nitrogen and the unadsorbed oxygen-enriched effluent is collected in a first surge vessel, the nitrogen-laden column is rinsed with a stream of high purity nitrogen gas withdrawn from a second surge vessel, the nitrogen-laden column is desorbed by application of vacuum thereto with the desorbed nitrogen effluent passing to said second surge vessel and repressurizing said column by admission of oxygen-enriched gas withdrawn from said first surge vessel;
Dependencies are inferred from the claim text.